Frost collector for open topped refrigerators



March 14, 1950 e. M. HAWLEY 2,500,679

FROST COLLECTOR FOR OPEN TOPPED REFRIGERATORS 2 Sheets-Sheet 1 Filed Jan. 8, 1948 INVENTOR- em/dM/fana/ey i. K J J ,9 OR/VEY.

March 14, 1950 G. M. HAWLEY 2,500,679

FROST COLLECTOR FOR OPEN TOPPED REFRIGERATORS Filed Jan. 8, 1948 2 Sheets-Sheet 2 //VVEN TOR.

- e/w/d M Haw/g A RNEK Patented Mar. 14, 1950 -UNITED 's 'rA'rEs PATENT OFFICE FROST COLLECTOR FOR OPEN TOPPED REFRIGERATOBS Gerald Mrllawlcy, Kansas City, Mo. Application January 8-, 1948, Serial No. 1,241

Claims.- (Cl. 62-895) The present invention relates in general to refrigeration and it deals more particularly with the form and construction of an improved refrigcrating unit.

'In the art of mechanical refrigeration the tendency for. frost to build up on the cold surfaces of the evaporator or freezing unit presents an important and troublesome problem. The accumulated icy coating reduces the efficiency of the system making it necessary to defrost the unit periodically, and by custom defrosting is inconvenlent, time consuming, messy and sometimes an expensive process.

One of the important objects of the present invention is to provide a simple and economical arrangement whereby the -frost may be removed and disposed of quickly andeasily without the usual mess and bother. I

Another object is to provide an improved form of open top cold storage cabinet, such as may be employed for example to store and display foodstuffs offered for salein grocery stores, delicatcssens and the like; a further object is to provide an improved form of refrigerated shelf struc- 'ture suitable for use in room size cold storage chambers.

Another object is to provide a one piece cold wall evaporator assembly adapted to be inserted into and removed from insulated cabinets of, different types as a unit.

According to the invention the surfaces of the cooling unit upon which frost would tend to accumulate are provided with a thin removable cover made of metal or other material having a high thermal conductivity; the frost deposits on the cover whereby defrosting may be effected simply by removing the cover periodically from the cooling unit and clearing it of the frost at a convenient place, preferably outside of the refrigerated zone. An important feature resides in the form and construction of the cover.

- Other objects and features will appear in the course of the following description of the invention.

taken along the line 6-6 of Fig. 5 in the direction of the arrows.

Referring first to Figs. 1, 2 and 3, the numeral ill indicates the-bottom of a cold storage cabinet or chest having vertical side walls i 2 and end walls l4. The walls are heavily insulated as shown, in order to prevent the transfer of heat therethrough, and it will be understood that the same is true of the bottom.

The top edges of thecabinet walls are rabbeted to provide a marginal recess is for receiving a removable horizontal lid or cover not shown. Assuming the cabinet is employedto store and display foodstuffs offered for sale in a grocery store, it is preferred that the lid be omitted from the cabinet throughout business hours and only employed to cover and close the cabinet overnight or between succeeding business days.

Secured to the side walls "approximately midway between the top and bottom of the cabinet are horizontal angle members i8 forming inwardly extending brackets adapted to support my shelf and cooling unit. The latter unit comprises a horizontal shelf 20 supporting a plurality of spaced vertical partitions 22 which are rigidly secured to the upper surface of the shelf by welding, brazing or by screws or the like; the shelf and partitions are double wall members with a zig-zag tube 24 in the space between the wallsof each member. The tubes in the partitions are connected in series as shown at 26 and are con-.

nected in series with the tube in the shelf 20 whereby they form a single continuous duct one end of which terminates in coupl ng 28 while the other terminates in coupling 30.

The unit just described forms an integral sub assembly adapted to be-inserted intoor removed from the cabinet in one piece. When in place, the

two ends of the aforementioned duct are connected by the couplings or unions 28 and 30 to pipes 32 and 34, these pipes in turn extending to conventional refrigerating apparatus not shown which serves to circulate the refrigerant through the duct in order to cool the interior of the cabinet.

Doors 36 are provided in one wall of the cabinet to give access to the space below shelf 20. Goods to be kept cool therefore may be stored both on the shelf and below the shelf.

My one piece shelf and cooling unit naturally is inserted in an open top chest of the type illustrated by lowering it into the chest until the unit rests on brackets l8, but it also is contemplated that the unit can be employed in cabinets having an opening in one wall rather than in the top; in the latter case insertion obviously will be effected by sliding the unit horizontally into the cabinet through the wall opening.

The tendency of frost to accumulate on a cold surface due to cooling the adjacent moist air below the frost point is well known. Continued accumulation of frost on the cooling coil or cooling wall of a refrigerating unit impairs its operation making it necessary to periodically remove the frost. In an open top cabinet of the type illustrated, the heaviness of the cooled air makes it lie in an inert mass within the chest, there being almost no movement or circulation of air below the rim of the cabinet. Accordingly after leaving an initial deposit of frost which is so light that it may be disregarded for all practical purposes, the main body of air in the cabinet is dry and hence produces no further frosting. However, the upper layers of air are disturbed at times, for example, as a result of the movement of air above the chest when people or objects pass by, as well as when goods are lifted into or out of the chest. For this reason the layer of air just below the rim of the cabinet is continuously or periodically interm xed with fresh, moisture laden air from outside of the chest, and consequently it has been found in practice that there is a pronounced tendency for frost to accumulate locally along the upper edges of the cold partitions 22.

These edges are provided with removable inverted U-shaped channels 38 upon which the frost builds up substantially as indicated by dot- .ted lines 40. In order to defrost the unit, it therefore is only necessary to lift the channels from their respective partitions, it being contemplated that they may be replacedby a fresh set of channels while the frost melts from them in a warm room, or, alternatively that the frost laden channels may be cleared at once, say by plunging them into hot water, wiped dry, and immediately restored to their positions on the respective partitions. In either event, the frost removal is eflected'easily and quickly without interrupting the normal'operation of the refrigerating equipment. No slush or objectionable litter of ice fragments is produced in the cabinet or upon the contents thereof, the operation being carried out cleanly andconveniently, without any mess whatever.

In large walk-in refrigerators or cold storage chambers of room size, it is customary to use tiers of shelves such as are shown in Fig. 5. The rectangular shelves 42 are supported at their corners by angle iron standards, diagonal braces 6 being provided to makethe structure rigid.

I Each shelf comprises a double wall having tubing 48 disposed between the two walls in a zig-zag pattern similar to that in shelf 20 (Fig. 1). The tubes of the superposed shelves are connected 4 in series by bridging tubes 50 as shown, and a refrigerant is circulated through the tubes by conventional refrigerating equipment connected thereto by couplings 52 and 54.

Frost normally accumulates over the whole area of each shelf in installations of this type, and in order to remove the frost it has been customary in the past to scrape them by hand with or without the application of heat to assist in loosening the accumulation. The operation, carried out as it is in a room maintained at freezing temperatures, is unpleasant and a threat to the health of the workmen. The scraping, particularly at the rear portions of the shelves, represents a difficult and strenuous task; and it leaves a litter of ice and slush on the floor of the room that not only increases the difficulty and hazard of the work but also presents an independent disposal problem.

I obviate all these difliculties simply by providing each shelf with a removable U-shaped sheath 55 made of thin sheet metal, the horizontal portions of the sheath hugging the top and bottom of the shelf whereby the frost accumulates on the sheath rather than upon the shelf proper. To defrost the unit, it is only necessary to withdraw the sheaths temporarily from the shelves, carry them outside of the refrigerated room and allow the frost to melt therefrom and run down a convenient drain. The process may, of course, be expedited, if desired, by the use of warm water or application of other heat, scraping, and the like.

With the aid of my sheaths the frost removal obviously can be efiected with much more convenience than when carried on by scraping the shelves themselves in the refrigerated chamber, and instead of littering the floor of. the chamber, the waste icy material can be deposited without mess or troublesome handling directly into a suitable receptacle, or flushed down a convenient drain.

From the foregoing it will be seen that this invention is one well adapted to attain all the ends and objects hereinbefore set forth together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

Inasmuch as various embodiments of the invention may be made without departing from the scope thereof, it is to be understood that all mat-- ter herein set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. Refrigeration equipment comprising an open top cabinet, inwardly extending brackets on the walls of the cabinet, a horizontal shelf resting on said brackets and positioned intermediate the top and bottom of the cabinet, a plurality of spaced vertical partitions rigidly amxed to the upper surface of the shelf, the upper edges of the partitions being on approximately the same level as the top of the cabinet, means in the shelf ar partitions forcooling sare, and a U-shaped channel inverted over the upper edge of each partition and removably supported thereon.

2. Equipment as in claim 1 wherein said cooling means comprises a continuous tubular duct extending through said shelf and partitions in series, said duct containing a refrigerant.

3. Refrigeration equipment comprising an open top cabinet, a plurality of vertical partitions in the cabinet having their upper edges on approxially spaced, parallel. flat walls with means therebetween for cooling same; a removable frost collecting sheath on each partition, each sheath comprising a web straddling the upper edge of the each channel comprising a thin sheath of heatconducting material hugging opposite sides of the partition.

4. Refrigeration equipment comprising an open topped cabinet, a plurality of vertical partitions in the cabinet having their upper edges on approximately the same level as the top of the cabinet, means in the partitions for cooling same, and a removable frost collecting shield on each partition, each shield comprising a U-shaped channel of thin metal inverted over the partition with opposite legs of the channe tensioned toward one another to frictionally eng ge opposite faces of the partition and provide efflcient thermal contact therewith.

5. In combination with an open top refrigerator cabinet having therein a plurality ofupright partitions whose upper edges are on approximately the same level as the top of the cabinet, each partition comprising a double wall unit having laterpartition with thin, dependent flanges of heat conducting material closely hugging opposite faces of the partition, said flanges tensioned toward one another to frictionally engage the two walls of the partition and provide eflicient thermal contact therewith.

GERALD M. HAWLEY.

REFERENCES cI'r'En The following references are of record in the tile of this patent:

UNITED STATES PATENTS Achs July 5, 1949 

